ata: Use dma_zalloc_coherent

Use the zeroing function instead of dma_alloc_coherent & memset(,0,)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/sata_fsl.c

@@ -734,13 +734,12 @@ static int sata_fsl_port_start(struct ata_port *ap)
 	if (!pp)
 		return -ENOMEM;
 
-	mem = dma_alloc_coherent(dev, SATA_FSL_PORT_PRIV_DMA_SZ, &mem_dma,
+	mem = dma_zalloc_coherent(dev, SATA_FSL_PORT_PRIV_DMA_SZ, &mem_dma,
 				  GFP_KERNEL);
 	if (!mem) {
 		kfree(pp);
 		return -ENOMEM;
 	}
-	memset(mem, 0, SATA_FSL_PORT_PRIV_DMA_SZ);
 
 	pp->cmdslot = mem;
 	pp->cmdslot_paddr = mem_dma;